Boating is a favored sports activity for many individuals, particularly during warmer periods of the year. Boating as an activity inofitself as well as for fishing occurs on lakes, rivers and oceans. Pleasure and fishing boats come in a number of different types and sizes. These boats are manually powered, such as canoes, kayaks, and rowboats, powered such as sailboats, catamarans, and the like, and power boats, such as ski boats, fishing boats, and cruisers.
Power boats use internal combustion motors as the power source for operating the boat. The motors are mounted in the boats as either an inboard motor or pivotally attached to a transom of the boat as an outboard motor. Both inboard and outboard power boats have air intakes for supplying air to the internal combustion motor. The air intake typically is an opening in a wall of a housing that encloses the engine. The opening connects to a passageway for communicating air to the engine. For example, an outboard motor is enclosed in a housing called a cowling. The cowling includes a port through which air for the engine passes. During operation of the engine, the port must be open for communicating air from the atmosphere to the engine. However, during operation of a pleasure boat, the outboard motor occasionally is covered with sprays of water or with waves. In those circumstances, water as well as air is communicated to the engine. Also, foreign matters sometime enter the engine through the air passageway. For example, flying insects are known to build nests inside the air intake, particularly when the boat is not used for an extended period of time. For instance, mud-dauber wasps are known to build nests in the port and passage that communicates air into the engine. Such foreign matters are detrimental to the engine and its operation. During operation, insects, dirt, dust and the like, can also be ingested into the engine.
The prior art describes various devices to reduce the ingestion of water through the air intake for the internal combustion engine. United States Patent No. 4,533,331 describes an outboard motor for pleasure craft having an air vent and water drain assembly on an underside surface of the power head housing forward of the engine. The underside surface of the power head housing provides a relatively protected area for air ventilation which is away from most splashing of water. A dome-shaped valve member is movably disposed in an opening of the assembly. An annular flange extends outwardly from the valve for sealingly engaging an outer surface of the bottom wall of the housing when the valve member is pushed inwardly into the opening. The valve member also includes interior ribs which extend laterally to contact an inner surface of the bottom wall. Gravity holds the valve member in a open position permitting air to enter through the assembly through a gap between the flange and the housing. When a wave or splash of water surrounds the housing, the dome-shaped valve is lifted upwardly. This pushes the flange against the bottom of the housing and seals the gap to block water from entering. Typically, the sealing is only momentary as the splash or wave passes over and beyond the motor. After the wave passes, the valve returns to its initial open position. Any water that may have entered prior to the valve closing then drains through the valve.
U.S. Pat. No. 4,518,363 describes a vent assembly on a power head housing for an outboard motor. The vent assembly includes a ball valve mounted in the bottom wall. Gravity holds the ball valve in an open position for allowing air flow in and out of the engine compartment. In the event water rises to a level above the housing bottom wall, the ball valve floats and sealingly engages the bottom wall to prevent entry of water into the engine compartment.
Other housings provide labyrinth-style flow paths for the air which is communicated to the engine. For example, U.S. Pat. No. 4,723,927 describes a housing for a marine drive outboard motor in which the air path reverses direction several times. The inner surfaces of the sides of the cowling include separators that separate water from the incoming fresh air. Upper vent openings in the separators allow the air to escape to the engine. Discharge openings communicate with the bottom of the separators to allow water to escape out of the cowling.
While devices such as these address the operational needs for momentarily sealing the air intake from entry of water to a marine motor, other conflicting needs are not addressed, particularly that of preventing infestation and nesting of insects in such.
It is thus seen that a need remains for an apparatus for permitting the flow of air to an outboard marine motor while preventing introduction of foreign matters into the air passage and restricting the inflow of water to the engine, in a more effective and efficient manner. It is to the provision of such that the present invention is primarily directed.